Many types of gas flow controllers have been implemented for a variety of applications. For example, a variety of known control arrangements for gas burners comprise a main valve, a servo valve and a servo controller, wherein the servo controller serves to control a gas output pressure by controlling the opening of the main valve. For the modulation of the gas output pressure an actuator is provided for the servo valve which makes the servo valve to open and close with a corresponding pulse width.
However, it is often that an increased safety standard is required in control arrangements for gas burners. Accordingly, an increased safety is required with respect to the closing of the main valve and an interruption of the flow of gas. Such safety standards are usually taken into account by a second main valve connected in series. In such a construction it is required that, even if one of the main valves is defective or fails, the flow of gas is safely interrupted. In most cases, however, such control arrangements permit little to no modulation of the pressure and the valve, respectively.